From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9833EB64D9 for ; Mon, 3 Jul 2023 01:33:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229777AbjGCBdw (ORCPT ); Sun, 2 Jul 2023 21:33:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229671AbjGCBdv (ORCPT ); Sun, 2 Jul 2023 21:33:51 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFBA712E for ; Sun, 2 Jul 2023 18:33:49 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4QvSzw3S8yz688Z4; Mon, 3 Jul 2023 09:30:52 +0800 (CST) Received: from localhost (10.34.206.101) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 3 Jul 2023 02:33:43 +0100 Date: Mon, 3 Jul 2023 09:33:39 +0800 From: Jonathan Cameron To: "nifan@outlook.com" CC: Fan Ni , "qemu-devel@nongnu.org" , "linux-cxl@vger.kernel.org" , "gregory.price@memverge.com" , "hchkuo@avery-design.com.tw" , "cbrowy@avery-design.com" , "ira.weiny@intel.com" , "dan.j.williams@intel.com" , Adam Manzanares , "dave@stgolabs.net" , "nmtadam.samsung@gmail.com" Subject: Re: [RFC 7/7] hw/mem/cxl_type3: add read/write support to dynamic capacity Message-ID: <20230703093339.00002fb2@Huawei.com> In-Reply-To: References: <20230511175609.2091136-1-fan.ni@samsung.com> <20230511175609.2091136-8-fan.ni@samsung.com> <20230515162212.0000275c@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.34.206.101] X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Wed, 28 Jun 2023 10:09:47 -0700 "nifan@outlook.com" wrote: > The 05/15/2023 16:22, Jonathan Cameron wrote: > > On Thu, 11 May 2023 17:56:40 +0000 > > Fan Ni wrote: > > > > > From: Fan Ni > > > > > > Before the change, read from or write to dynamic capacity of the memory > > > device is not support as 1) no host backed file/memory is provided for > > > it; 2) no address space is created for the dynamic capacity. > > > > Ah nice. I should have read ahead. Probably makes sense to reorder things > > so that when we present DCD region it will work. > > We can back dynamic capacity with host memory/file and create address > space for dc regions, but until extents can be added we should not expect > any read/write can happen to the dynamic capacity, right? True. Seems logically 'unusual' though to set up the routing etc, but not plumb the actual memory access i until later. I guess it all comes together in the end and doing it this way lets you handle the extent mapping later. So fine to leave it as you have it. Jonathan